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| author | Christoph Hellwig <hch@lst.de> | 2014-07-08 12:25:28 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-07-31 12:52:54 -0700 |
| commit | 0b9f20dad0bc659261f88294192c1f1c7763fc2a (patch) | |
| tree | 552aa8cc04f63f92070a3a5b59cffd3d191f1457 /block | |
| parent | 3b968e0cc905310a19bc0b8f0f77600abf1aed2d (diff) | |
| download | lwn-0b9f20dad0bc659261f88294192c1f1c7763fc2a.tar.gz lwn-0b9f20dad0bc659261f88294192c1f1c7763fc2a.zip | |
block: don't assume last put of shared tags is for the host
commit d45b3279a5a2252cafcd665bbf2db8c9b31ef783 upstream.
There is no inherent reason why the last put of a tag structure must be
the one for the Scsi_Host, as device model objects can be held for
arbitrary periods. Merge blk_free_tags and __blk_free_tags into a single
funtion that just release a references and get rid of the BUG() when the
host reference wasn't the last.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-tag.c | 33 |
1 files changed, 7 insertions, 26 deletions
diff --git a/block/blk-tag.c b/block/blk-tag.c index 3f33d8672268..a185b86741e5 100644 --- a/block/blk-tag.c +++ b/block/blk-tag.c @@ -27,18 +27,15 @@ struct request *blk_queue_find_tag(struct request_queue *q, int tag) EXPORT_SYMBOL(blk_queue_find_tag); /** - * __blk_free_tags - release a given set of tag maintenance info + * blk_free_tags - release a given set of tag maintenance info * @bqt: the tag map to free * - * Tries to free the specified @bqt. Returns true if it was - * actually freed and false if there are still references using it + * Drop the reference count on @bqt and frees it when the last reference + * is dropped. */ -static int __blk_free_tags(struct blk_queue_tag *bqt) +void blk_free_tags(struct blk_queue_tag *bqt) { - int retval; - - retval = atomic_dec_and_test(&bqt->refcnt); - if (retval) { + if (atomic_dec_and_test(&bqt->refcnt)) { BUG_ON(find_first_bit(bqt->tag_map, bqt->max_depth) < bqt->max_depth); @@ -50,9 +47,8 @@ static int __blk_free_tags(struct blk_queue_tag *bqt) kfree(bqt); } - - return retval; } +EXPORT_SYMBOL(blk_free_tags); /** * __blk_queue_free_tags - release tag maintenance info @@ -69,28 +65,13 @@ void __blk_queue_free_tags(struct request_queue *q) if (!bqt) return; - __blk_free_tags(bqt); + blk_free_tags(bqt); q->queue_tags = NULL; queue_flag_clear_unlocked(QUEUE_FLAG_QUEUED, q); } /** - * blk_free_tags - release a given set of tag maintenance info - * @bqt: the tag map to free - * - * For externally managed @bqt frees the map. Callers of this - * function must guarantee to have released all the queues that - * might have been using this tag map. - */ -void blk_free_tags(struct blk_queue_tag *bqt) -{ - if (unlikely(!__blk_free_tags(bqt))) - BUG(); -} -EXPORT_SYMBOL(blk_free_tags); - -/** * blk_queue_free_tags - release tag maintenance info * @q: the request queue for the device * |